Shrinkproofing of wool



United States Patent 3,466,136 SHRINKPROOFING OF WOOL William L. Wasley,Berkeley, Robert E. Whitfield, Pleasant Hill, and Lowell A. Miller,Walnut Creek, Calif., assignors to the United States of America asrepresented by the Secretary of Agriculture No Drawing. Filed Mar. 17,1964, Ser. No. 352,700

Int. Cl. D06m 3/06 US. Cl. 8127.5 12 Claims A non-exclusive,irrevocable, royalty-free license in the invention herein described,throughout the world for all purposes of the United States Government,with the power to grant sublicenses for such purposes, is hereby grantedto the Government of the United States of America.

This invention relates to and has among its objects the provision ofnovel methods for treating textile materials, particularly wool, toachieve shrinkproofing and other desirable effects. Further objects andadvantages of the invention will be evident from the followingdescription wherein parts and percentages are by weight, unless otherwise specified.

In the patent of Miller, Whitfield, and Wasley (3,078- 138, granted Feb.19, 1963) there are disclosed processes combined therewith. In a typicalembodiment of their process, a wool fabric is serially impregnatedwithtwo solutions--the first being a solution of a'diarnine in water, thesecond being a solution of a diacid chloride in a waterimmiscible,volatile, inert solvent. By such treatment the fibers are coated withsuperposed layers of the mutually} insoluble solutions: an inner layerof diamine in water and an outer layer of diacid chloride inwater-immiscible solvent. Under these conditions the diamine and diacidchloride react almost instantaneously at the interface between thephases, producing in situ on the fibers a highmolecular weight, resinouspolyamide which coats the fibers and renders the fabric shrinkproofwithout detriment to the hand, porosity, and other valuable propertiesof, the fabric. Moreover, the polyamide is chemically .hdnded to thewool so that the shrinkproofing effect is highly durable, i.e., thepolyamide deposit is not removed by repeated washing of the treatedfabric in conventional soap and water or detergent and water launderingformulations, or in conventional dry-cleaning formulations. From aprocedural standpoint, the process has the advantage of simplicity andrapidity in that the basic operation is simply a serial impregnation ofthe fabric in the two solutions. Another point is that the process doesnot re- 3,466,136 Patented Sept. 9, 1969 ice attained without anydegradation or weakening of the fibers. Moreover, such importantcharacteristics of the fiber as hand, porosity, resiliency, etc. are notharmed. On the other hand, in conventional setting procedures involvingthe application of reducing agents per se to wool textiles, a weakeningof the fibers is an invariable sideeffect. A further advantage of theprocess of the invention is that the setting is attained Withoutdetriment to the desired shrinkproofing effect. As a matter of fact, ourinvestigations have shown that a better shrinkproofing elfect isattained for a given amount of polymer formed on the wool fibers. It isthus evident that the use of a reducing agent in conjunction with theaforesaid interfacial polymerization system unexpectedly provides asynergistic effect.

For use in the process of the invention, a preferred class of reducingagents comprises the inorganic salts which provide sulphide ions inaqueous: solution. Typical of this class are the alkali metal, alkalineearth metal, ammonium, etc. sulphides and hydrosulphides. Another veryuseful class of reducing agents comprises the organic compoundscontaining a thiol group, as, for example,

thioglycollic acid, or its salts such as the alkali metal or ammoniumsalts; beta-mercapto ethanol; monthio glyt cerol; .dithio-glycerol;butyl mercaptan; thiornalic acid or its, salts; .thio-lactic acid or itssalts; thiophenol; thiocresol;

" .jetrijother reducing agents which may be used are listed below by wayof illustration: Formamidine sulphinic acid, also known asiminoaminomethane sulphinic acid betaine. Formaldehyde sulphoxylates,generally used in the form of their alkali metal, zinc, or ammoniumsalts. Alkali metal or ammonium sulphites, bisulphites andhydrosulphites. Aldehyde or ketone addition products with sulphites orbisulphites, e.g., sodium formaldehyde bisulphite, sodium acetonebisulphite, etc. Generically, the reducing agents used in accordancewith the invention may be defined as sulphur-containing, reductive,disulphidesplitting agents because of the fact that they all containsulphur in their structures and because they have the ability to openthe disulphide (cystine) linkage in the wool molecule, generallyconverting a single disulphide (SS) bond into'two thiol (-SH groups.

The amount of reducing agent is not critical and may be varied dependingon such circumstances as the efficacy of the agent selected, thedurability of set desired in the product, the character of the fibersbeing treated, etc. Even minute amounts of the reducing agent willprovide some degree of improvement over the known techniques.

- Usually, the reducing agent is used in an amount from quire any heatcuring of the treated fabric as is commonly necessary in most resinshrinkproofing procedures.

In accordance with the present invention, the basic principles of theaforesaid processes are applied in conjunction with the use of certainadditives (to the treatment solutions) whereby to achieve advantageousresults over and above those attained by the patented procedures.

One phase of the invention involves the addition of a reducing agent toone of the complementary treating solutions, preferably to the diaminesolution. A primary advantage obtained thereby is that when the Productis subsequently subjected to a conventional setting treatment (heatingwhile constrained in a predetermined shape), it acquires a permanentset. Accordingly, when the fabric or garments made therefrom aresubjected to such stresses as crushing, folding, or use in the rain orother humid conditions, they remain essentially free from wrinkles orcreases. Moreover, this set is maintained even when the material issubjected to repeated washing or dry cleaning. Another advantage is thatsuch desirable setting effect is about 0.1 to 5 parts per part ofdiamine in the treating solution. To avoid possibility of degradation ofthe textile material when it is contacted with the treating solution, itis generally preferred to limit the maximum concentration of thereducing agent to less than 0.5 molar, preferably not more than about0.2 molar. For best results it is preferred to use the reducing agentsin. conjunction with an alkaline agent to raise the pH of the solutionof reducing agent plus diamine to a level of about 12 to 13. With someof the reducing agents, such as the alkali metal sulphides, additionalalkaline material will not usually be necessary because of the stronglybasic character of the sulphides. With other reducing agents such as )8-mercaptoethanol, thioglycollic acid etc, one may addadditional alkalinematerial such as an alkali metal hydroxide, carbonate, or, morepreferably, an alkali metal metasilicate or dithiocarbamate. Theadvantages to be gained from such compounds are explained hereinbelow inconnection with another phase of the present inven- O and (2) diacidchloride in water-immiscible solvent, a polyamide resin is formed andthis resin is chemically bonded (grafted) to the Wool, to a greater orlesser extent, depending on the conditions of reaction. It is postulatedthat when a reducing agent is present in the environment, reactive sitesare opened up in the wool molecules-fr example, through splitting ofdisulphide linkages. The resulting free thiol groups are then availablefor combination with acid chloride or other reactive groups. Since thesaid reactive sites are added to those already present, it is believedthat the resin is grafted to the wool to a greater extentthe resin ismore tightly locked to the wool fibers and thus the shrinkage protectionis more effective and more resistant to removal by repeated washing.

In a typical practice of the present invention, the procedure of Patent3,078,138 is employed with, of course, the change that the reducingagent is added. Thus the textilein the form of garments, fabris, yarn,roving, top, etc.-is entered into an aqueous solution containing adiamine plus the reducing agent. After the textile has been impregnatedwith this solution it is pressed to remove excess liquid. Then, it isimpregnated with the second solution, for example, a solution of adiacid chloride in a volatile, inert, Water-immiscible solvent. Afteranother pressing to remove excess liquid, the textile is washed in warmwater containing a small proportion of a soap or synthetic detergent andrinsed in order to remove unreacted materials and particles of resinousreaction product which are not firmly attached to the textile fibers.Following this, the textile is dried and then treated to establish thepermanent set. This is done in conventional manner and simply involvesarranging the material in a desired pattern and applying heat whileconstraining it in such pattern. For example, if a fiat set is desired(as in the case with ordinary yardage) the product is subjected to astandard semi-decating procedure. This involves winding the fabric,sandwiched between smooth cotton cloth, onto the hollow, perforatedshaft of the semi-decater device. Steam is then caused to flow into theshaft, through the perforations, and through the layers of wound-upfabric. After such steaming for a few minutes, the supply of steam iscut off and the hollow shaft is connected to a source of vacuum to drawair through the fabric layers and so cool them. It is obvious that if-itis desired to set the fabric in a pattern other than a fiat one, one canapply other conventional setting techniques. For example, to form thematerial into pleats it may be folded into the desired arrangement ofpleats and the resulting package of pleated material tied into a bundleand placed in a chamber where it is steamed to set the fabric in thepleated arrangement. It is obvious from the above that one can use anyof the conventional systems which involve arranging the material in apredetermined physical configuration and, while holding in such state,subjecting it to heat applied by the use of live steam, hot platens orrollers etc. Such systems are, of course, well known in the art and theinventors herein claim no novelty in such procedures, per se. Moreover,since the invention provides useful advantages, e.g., improvedshrinkproofing, whether or not a setting treatment is applied, it iswithin the ambit of the invention to apply reducing agents as describedhereinabove in a tool system where no setting treatment is applied.

In accordance with another phase of the present invention, the basicprinciples of the aforesaid Miller et al. process (3,078,138) areapplied in conjunction with certain additives-a silicate or adithiocarbamate-whereby to achieve advantageous results over and abovethose obtained by the patented procedures. Thus, it has been obserbedthat by addition of a silicate or a dithiocarbamate to the treatingsolutionspreferably to the diamine solution-an enhanced shrinkproofingeffect is attained. For a given amount of polymer formed on the fibers agreater degree of shrinkage protection is obtained. Also, it has beenfound that the additives yield products with a better hand. Moreover,these valuable advantages are attained without any detriment to thefibersthere is no degradation or weakening of the fibers nor reductionin porosity or resilience of the treated material. As the silicate,sodium metasilicate is preferred. However, other alkali metal silicatesmay be used, for example, alkali metal metasilicates, ortho silicates,or any of the molecularlydehydrated silicates, or polysilicates as theymay be termed, such as Na Si O Na Si O Na Si O etc. As thedithiocarbamate, we prefer to use ethylene bis-(sodium dithiocarbamate)which has the formula s s NaSi 1N H-CHz-CHz-NH-iL-S-N a As well known inthe art, dithiocarbamates are prepared by reacting a primary orsecondary amine with carbon bisulphide in the presence of a base such assodium hydroxide whereby a hydrogen atom attached to nitrogen isreplaced by the radical In the process of the invention one can use anyof such compounds, derived, for example, from aliphatic, aromatic, orheterocyclic amines, wherein at least one hydrogen atom attached tonitrogen is replaced by the group (wherein M is a metal such as analkali metal). Typical of the compounds which may be used are propylenebis- (sodium dithiocarbamate), tetramethylene bis-(sodiumdithiocarbamate), paraphenylene bis-(sodium dithiocarbamate), piperazinebis-(sodium dithiocarbamate), sodium ethyl dithiocarbamate, sodiumphenyl dithiocarbamate, sodium piperidyl dithiocarbamate, etc.

The amount of the agent (silicate or dithiocarbamate) is not criticaland may be varied depending on such circumstances as the efiicacy of theagent selected, the character of the fibers being treated, the degree ofimprovement in shrinkproofing desired, etc. Even small amounts of theagents will provide some degree of improvement over the knowntechniques. The agents in question are strongly alkaline and are usuallyused in such amount as to raise the pH of the diamine solution to above12. At this point it may be mentioned that Miller et al. (3,078,138)advocate addition of an alkaline agent-such as alkali metal hydroxide orcarbonate-to the diamine solut1on to act as an HCl-acceptor, that is, totake up the hydrogen chloride formed in subsequent reaction of thediamine with the diacid chloride. However, in accordance with thepresent invention, it is not just a matter of HCl-acceptance. Althoughthe agents used herein are alkaline substances, they provide resultsover and above anything which could be attributed to their merealkalinity. For example, addition of sodium carbonate in amount adequatefor HCl-acceptance does not yield the results obtained as describedherein when, for example, sodium metasllicate or ethylene bis-(sodiumdithiocarbamate) is added to the diamine solutionnote Examples 2 and 3,below. Moreover, although the alkali metal hydroxides suggested byMiller et al. are useful as HCl-acceptors, they exert such a corrosiveaction that the wool fibers being treated are damaged-they develop aharsh hand totally unlike the smooth hand attained When wool fabrics aretreated in accordance with the present invention, using silicates ordithiocarbamates as the additive. Thus, although alkali metal hydroxidesare useful additives for HCl-acceptance, they cannot provide thecombination of desirable results-improved shrinkage control plusretention of the hand of the textileobtained with the additives used inaccordance with the present invention.

The effectiveness of silicates and dithiocarbamates is believed toinvolve the following mechanism: In the known practice, there is alikelihood that the diamine in the treating solution will react with COfrom the atmosphere, yielding reaction products such as carbamates andcarbonates which interfere with proper amine-diacid chloridecondensation. However, it is postulated that the added silicate (ordithiocarbamate) prevents or minimizes this diamine-CO reaction with thenet result that the diamine is utilized fully in the desiredcondensation with the diacid chloride. Another point is that it isbelieved that the silicate (or dithiocarbamate) has the effect ofopening up reactive sites on the wool molecules. Since these reactivesites are added to those already present, it is believed that therebythe resin (subsequently formed by condensation of the diamine and diacidchloride) is grafted to the wool to a greater extent, i.e., the resin ismore tightly locked to the wool fibers and thus the shrinkage protectionis more effective and more resistant to removal by repeated washings.

In a typical practice of the present invention, the procedure of Patent3,078,138 is employed with, of course, the change that the silicate ordithiocarbamate is added. Thus the textile material-in the form ofgarments, fabrics, yarn, roving, top, etc.is entered into an aqueoussolution containing a diamine plus the added silicate ordithiocarbamate. After the textile has been impregnated with thissolution, it is pressed to remove excess liquid. Then, it is impregnatedwith the second solution, for example, a solution of a diacid chloridein a volatile, inert, water-immiscible solvent. After another pressingto remove excess liquid, the textile is wased in Warm water containing asmall proportion of a soap or synthetic detergent and rinsed, thus toremove unreacted materials, particles of resin not firmly bonded to thefibers, ect. Following this, the textile is dried. Other conventionaltreatments such as dyeing, shearing, pressing, semi-decating, etc. maybe applied as desired.

In the above description we have stressed application of the inventionto a system Where the polymer formed in situ in the textile material isproduced by the interfacial reaction of a diamine and a diacid chloride.In its broad aspect, the invention encompases the utilization of any ofthe reaction systems -disclosed in Patents 3,078,138, 3,084,0l8,3,084,019 and 3,093,441-where one of the reactants is a diamine and theother is a bifunctional compound capable of forming polymers with thediamine. Typical of these bifunctional compounds are diacid, chlorides,bischloroformates, diisocyanates, and mixtures thereof. In cases where adiacid chloride is used, the polymer formed is a polyamide; where abischloroformate is used, the polymer is a polyurethane; where adisocyanate is used, the polymer is a polyurea. By using mixtures ofbifunctional compounds, interpolymers may be produced. Typical of thelast is the use of a diamine in conjunction with a mixture of a diacidchloride and a bischloroformate to produce a type of interpolynter whichmay be termed a copoly amide-urethane. Accordingly, in its broad aspectthe invention encompasses application of the critical factors describedabove in connection with any system for shrinkproofin'g which involvesserial impregnation of a wool textile with (1) an aqueous diaminesolution and then with (2) a solution of a bifunction-al compoundcapable of forming a polymer with the diamine, said second solutionhaving as its solvent an inert, essentially 'waterdmmiscible solvent. Asnoted above, typical of the bifunctional compounds which can be employedin the second solution are acid chlorides, bischloroformates,diisocyanates, and mixtures thereof. By applying these types ofcompounds in serial manner and in essentially mutually-immisciblephases, various types of polymers may be formed in situ on the woolfibers, rendering the textile shrinkproof. Typical examples of compoundswhich can be employed in a practice of the invention are describedbelow.

As the diamine one may employ any of the aromatic,

aliphatic, or heterocyclic compounds containing two primary or secondaryamine groups, preferably separated by at least two carbon atoms. Thedliamines may be substituted if desired with various non-interferring(nonfunctional) substituents such as ether radicals, thioether radicals,tertiary amino groups, sulphone groups, fluorine atoms, etc, Typicalcompounds in this category are listed below merely by way ofillustration and not by way of limitation: ethylene diamine;trimethylene diamine; tetramethylene diamine; hexamethylene diamine;octamethylene diamine; decamethylene diamine; N, N'-dimethyl-l,3-propanediamine; l,2-diamino2-methylpropane; 2,7-diamino 2,6dimethyloctane; N,N-dirnethyl-l,6-hexanediamine; 1,4-diaminocyclohexane; 1,4-bis-(aminomethyl) cyclohexane; 2,2-diaminodiethylether; 2,2-diaminodiethyl sulphide; bis-(4-aminocyclohexyl) methane;N,N- dimethyl-2,2,3,3,4,4-hexafiuoropentane 1,5 diamine; ortho-, meta-,or para-phenylene diamine; benzidine; xylylene diamine; m-toluylenediamine; orthotolidine; piperazine, and the like. If desired, mixturesof different dia'mines may be used. It is generally preferred to usealiphatic alpha, omega diamines, particularly of the type wherein n hasa value of 2 to 12, preferably 6 to 10. Particularly preferred inhexamethylene diamine, i.e., the compound of the above formula wherein11:6.

As the diacid chloride one may employ any of the aliphatic, aromatic, orheterocyclic compounds containing two carbonylchloride (-COCl) groups,preferably separated by at least two carbon atoms. The diacid chloridesmay be substituted if desired with non-interfering (non-functional)substituents such as ether groups, thioether groups, sulphone groups,etc. Typical examples of compounds in this category are listed belowmerely by way of illustration and not limitation: oxalyl chloride,maleyl chloride, fumaryl chloride, malonyl chloride, succiny chloride,glutaryl chloride, adipyl chloride, pirneyl chloride, suberyl chloride,azelayl chloride, sebacyl chloride, cyclohexane-1,4-biscarbonylchloride, phtha'lyl chloride, isophthalyl chloride, terephthalylchloride, 4,4'-biphenyl-dicarbonyl chloride, ,B-hydromucony'l chloride,

ClCOCH CI-I=CHCH COCl diglycollic acid chloride, i.e.

O(CH -COCl) higher homologues of this compound as dithiodigycollic acidchloride, diphenylolpropanediacetic acid chloride, i.e.

(CH C(C H OCH COCl) 2 and the like. If desired, mixtures of differentdiacid chlorides may be used. It is also evident that the sulphuranalogues of these compounds may be used and are included Within thespirit of the invention. Thus, instead of using compounds containing twoCOC1 groups one may use compounds containing one CSCl and one --COC1group or compounds containing two CSCl groups. Moreover, although thediacid chlorides are preferred as they are reactive and relativelyinexpensive, the corresponding bromides and iodies may be used.

As the diacid chloride, it is generally preferred to use the aliphaticcompounds containing two carbonylchloride groups in alpha, omegapositions, particularly those of the type:

wherein n has a value from 2 to 12. Another preferred category includesthe compounds of the formula ClCOA-COC1 '(Where A is the benzene orcyclohexane radical), especially para-substituted compounds such asterephthalyl and hexahydroterephthalyl chlorides.

As the bischloroformate one may use any of the aliphatic, aromatic, orheterocyclic compounds containing two chloroformate groups preferablyseparated by at least two carbon atoms. The bischlorofor-mates may besubstituted if desired with non-interfering (non-functional)substituents such as sulphone groups, ether groups, thioether groups,etc. Typical examples of compounds in this category are listed belowmerely by way of illustration and not limitation: ethylene glycolbischloroformate, diethylene glycol bischloroformate, 2,2-dimethylpropane 1,3-diol bischloroformate, propane-1,3-diol bischloroformate,butane-1,4-diol bischloroformate, hexane 1,6 diol bisch'loroformate,octane-1,8-diol bischloroformate, decane 1,10-di0l bischloroformate,butane-1,2-dio1 bischloroformate, hexane-1,2-di0l bischloroformate,Z-methoxyglycerol-1,3-bischloroformate, glycerol 1,2 bischloroformate,glycerol-1,3-bischloroformate, diglycerol bischloroformate, hexanetriolbischloroformate, pentaerythritol bischloroformate, cyclohexane-lA-diolbischloroformate, hydroquinone bischloroformate, resorcinolbischloroformate, catechol bischloroformate, bischloroformate of2,2-bis(parahydroxyphenyl) propane, bischloroformate of2,2-bis(parahydroxyphenyl) butane, bischloroformate of4,4-dihydroxybenzophenone, bischlorofor mate of1,2-bis(parahydroxyphenyl) ethane, naphthalene- 1,5-diolbischloroformate, biphenyl-4,4-diol bischloroformate, etc. If desired,mixtures of different bischloroformates may be used.

Among the preferred compounds are the aliphatic bischloroformates, forexample, those of the type:

II CICO' (CHZ)L1 OPJCI wherein n has a value from 2 to 12. Anotherpreferred category of compounds are the bis-chloroformates derived frompolyethylene glycols, e.g.

it ClCOCH;-OH -[O OH ClI2]uO oIr2o1I2-o C-Cl wherein n has a value fromzero to 10. A useful category of aromatic bischloroformates are thebisphenol chloroformates, that is, compounds of the type:

wherein RC-R represents an aliphatic hydrocarbon group containing 1 to12 carbon atoms and R is hydrogen or a low alkyl radical.

It is also evident that the sulphur analogues of the bischloroformatesmay be used and such are included within the spirit of the invention.Thus, instead of using the compounds containing two group one may useany of the compounds containing the sulphur analoges of these groups,for example, the compounds containing two groups of the formula it XCClwherein one X is sulphur and the other is oxygen or wherein both Xs aresulphur. Moreover, although the bischloroformates are preferred becausethey are reactive and relatively inexpensive, it is not essential thatthey contain chlorine and one may use the corresponding bisbromoformatesor bisiodoformates.

As the diisocyanate one may employ any of the aliphatic, aromatic, orheterocyclic compounds containing two isocyanate (-NCO) groups,prefer-ably separated by at least two carbon atoms. The diisocyanatesmay be substituted if desired with non-interfering (nonfunctional)substituents such as ether groups, thioether groups, sulphone groups,etc, Typical examples of compounds in this category are listed belowmerely by way of illustration and not limitation: ethylene diisocyanate,propylene diisocyanate, butylene diisocyanate, trimethylenediisocyanate, tetramethylene diisocyanate, haxamethylene diisocyanate,octamethylene diisocyanate, decamethylene diisocyanate, cyclohexylenediisocyanate, bis(2-isocyanatoethyl) ether, bis(2-isocyanatoethyl) etherof ethylene glycol, o-phenylene diisocyanate, m-phenylene diisocyanate,p-phenylene diisocyanate, tolylene-2,4-diisocyanate,tolylene-Z,6-diisocyanate, 3,3-bitolylene-4,4'-diisocyanate,

diphenyl ether-4,4'-diisocyanate, i.e.

3,5,3',5 -bixy1ylene-4,4-diisocyanate, i.e.

I I R R diphenylmethane-4,4'-diisocyanate, i.e.

biphenylene diisocyanate, 3,3 dimethoxy-biphenylene- 4,4-diisocyanate,naphthalene diisocyanates, polymethyl polyphenyl isocyanates, etc. It isalso evident that the sulphur analogues of these compounds may be usedand such are included within the spirit of the invention. Thus forexample, instead of using the compounds containing two NCO groups onemay use their analogues containing either two NCS groups or one -NCOgroup and one NCS group. Another point to be made is that it is withinthe spirit of the invention to utilize the derivatives which yield thesame products with compounds containing active hydrogen as do theisocyanates. Particular reference is made to the biscarbamyl chlorideswhich may be used in place of the diisocyanates, Thus one may use any ofthe above-designated compounds which contain carbamyl chloride groups (Ris CH3) or their sulphur analogues i (-NCCl) in place of the isocyanategroups. Among the preferred compounds are the aliphatic diisocyanates,for example, those of the type OCH( CH -NCO wherein n has a value from 2to 12. Other preferred compounds are the tolune diisocyanates, xylyenediisocyanates, and diphenylmethane-4,4'-diisocyanate which may also betermed methylene-bis(p-phenylisocyanate).

Since the process of the invention makes use of an interfacialpolymerization (formation of a polymer at the interface betweenmutually-immiscible phases of the individual rectants), it is evidentthat the polymer-forming agents need be applied in solutions wherein thesolvents are substantially mutually immiscible. Thus the diaminereactant is applied in aqueous solution while the complementary reactant(diacid chloride, bischloroformate, or

diisocyanate is applied as a solution in an inert, essentiallywater-immiscible solvent, preferably one which is volatile, for example,benzene, carbon tetrachloride, toluene, xylene, ethylene dichloride,chloroform, hexane, octane, petroleum ether, or other volatile petroleumhydrocarbon mixture. It is generally preferred that the solution of thecomplementary reactant be dilute; that is, it should contain about /2 topreferably /2 to 2%, of the reactant. Generally, the conditions oftreatment, such as the rate of traversal of the fabric, concentration ofthe reactants, degree of pressing, etc., are so correlated that theproduct contains about 0.25 to 3% of polymer.

Ordinarily, no reaction promoters are required in the reactivesolutions. However, one may add such agents as tertiary amines to theaqueous diamine solution. Other typesof agents which may be added to thediamine solution or to the solution of the complementary reactant aretributyl tin chloride, stannous tartrate, ferric chloride, titaniumtetrachloride, boron trifluoride-diethyl ether complex, or tin salts offat acids such as tin laurate, myristate, etc.

To aid the diamine solution in penetrating into the textile, it isgenerally preferred to incorporate a minor proportion of asurface-active agent into this solution. For this purpose one may usesuch agents as sodium alkyl (C -C sulphates, the sodium alkane (C Csulphonates, the sodium alkyl (C C benzene sulphonates, esters orsulphosuccinic acid such as sodium dioctylsulphosuccinate, and soaps,typically sodium salts of fat acids. Surface-active agents of thenon-ionic type may also be used and they have the desirable property ofbeing non-substantive; that is, they are not preferentially absorbed bythe wool. Typical examples of nonionic agents are the reaction productsof ethylene oxide with fatty acids, with polyhydric alcohols, withpartial esters of fatty acids and polyhydric alcohols or with alkylphenols, etc. Typical of such agents are a polyoxyethylene stearatecontaining about oxyethylene groups per mole, a polyoxyethylene ether ofsorbit-an monolaurate containing about 16 oxyethylene groups per mole, adistearate of polyoxyethylene ether of sorbitol containing about 40oxyethylene groups per mole, iso-octyl phenyl ether of polyethyleneglycol, etc. A useful class of non-ionic agents are the nonylphenoxypolyethyleneoxy ethanols, containing 9 to 12 moles of ethylene oxide permole of nonylphenol, as these compounds are readily soluble in thediamine solution even in the presence of relatively high concentrationsof sodium carbonate. Generally, only a small proportion of surfaceactiveagents is used, on the order of 0.05 to 0.5%, based on the weight of thesolution. In addition to, or in place of the surface-active agent, asupplementary solvent may be added to the primary solvent (water) inquantity suflicient to disperse the active reactant. For such purposeone may employ acetone, or other iner-t, volatile solvent, particularlyone that is at least partially miscible with water.

In the foregooing description we have emphasized the utilization of ourinvention in connection with the shrinkproofing of wool. However, Woolis by no means the only substrate which can be treated. In its broadaspect, the invention can be utilized in the treatment of any fibrousmaterial. Typical examples of such materials are animal hides; leather;animal hair; cotton; hemp; jute; ramie; linen; wood; paper; syntheticcellulosic fibers such as viscose, cellulose acetate, celluloseacetatebutyrate; casein fibers; polyvinyl alcohol-protein fibers;alginic fibers; glass fibers; asbestos; and organic noncellulosic fiberssuch as Poly (ethylene glycol terephthalate), polyacrylonitrile,polyethylene, polyvinyl chloride, polyvinylidene chloride, etc. Suchapplications of the teachings of the invention may be for the purpose ofobtaining functional or decorative effects such as sizing, finishing,increasing gloss or transparency, increasing water-repellency,increasing adhesionor bonding-characteristics of the substrates withrubber, polyester resins, etc. The process of the invention is ofspecial advantage as applied to hydrogen-donor textiles, for example,protein and cellulosic fibers, because these are especially adapted forchemical bonding of the resin to the fiber molecules.

In utilizing the present invention for the shrinkproofing of longlengths of wool textiles on a continuous basis, it is preferred toinclude in the total system the features disclosed in the copendingapplication of Fong, Brown, Wasley, Whitfield and Miller, Ser. No.174,315, filed Feb. 19, 1962 and in the copending application of Millerand Pong, Ser. No. 325,195, filed Nov. 20, 1963. Although these featuresform no part of the present invention, they are explained herein toprovide a complete description of the preferred environment in which topractice the present invention. The features in question are describedin the following paragraphs, numbered 1 to 6:

1) Condition of wool.-The wool prior to entering the first (diamine)solution should be in a neutral or alkaline state. If for any reason itis in an acid state, it is preferably to soak it in an aqueous solutionof an alkaline agent, such as sodium carbonate, to remove the acidity.

(2) Temperature of the diamine solution.To attain rapid penetration ofthe solution into the textile and to enhance exhaustion of the diamineonto the fibers, it is preferred to have the solution at an elevatedtemperature, e.g., at about IUD-150 F.

(3) Time of contact between wool and diamine solution.-The textileshould be maintained in the diamine solution for a period long enoughfor the solution to thoroughly penetrate into the material and for thediamine to exhaust out onto the fibers. In continuous operation this canbe ensured with slowing down the production rate by threading thematerial back and forth in the solution.

(4) Removal of excess diamine solution.--After leaving the diaminesolution, the textile is treated-as by efficient pressing or applicationof vacuum-to remove all the excess solution which is loosely associatedwith the material as in the form of surface deposits or collected ininterstices between individual fibers.

(5 Final padding.--After the textile leaves the second (diacid chloride)solution, it is pressed at high pressure, for example, at at least lbs.per linear inch, to enhance the shrinkproofing effect.

(6) In continued operation of the system, material from the first(diamine) solution will be detached from the textile and mixed with thesecond (diacid chloride) solution. This causes problems such asevolution of corrosive HCl fumes, excessive consumption of diacidchloride, etc. The problems are readily obviated by continuously pumpingthe second solution through a molecular sieve, such as a natural orsynthetic zeolite, which adsorbs water and HCl from the solution andalso filters out any particles of suspended matter or sludge.

The invention is further demonstrated by the following illustrativeexamples:

Standard wash procedure for shrinkage test.The tests for shrinkagereferred to below were conducted in the following manner: The woolsamples were washed in a reversing agitator-type household washingmachine, using a three-pound load, a water temperature of F., and alow-sudsing detergent in a concentration of 0.1% in the wash liquor. Thewash cycle itself was for 75 minutes, followed by the usual rinses andspin-drying. In most cases this washing program was repeated severaltimes. The damp material was then tumble-dried in a householdtypeclothes dryer. The samples were then measured to determine their lengthand width and the shrinkage calculated from the original dimensions.

Fabric breaking strength.-ASTM Method D 39-40, cut strip method, 6-inchx 1 inch samples, 3-inch gauge, 20 seconds to break.

1 1 EXAMPLE 1 Solution A.Aqueous solution containing hexamethylenediamine, sodium carbonate, and a reducing agent, in concentrationsspecified below.

Solution B.-3% sebacoyl chloride in a petroleum distillate (Stoddardsolvent).

An all-wool worsted fabric was treated, in continuous operation, in thefollowing manner: Immersion in solu- Area shrinkage, percent Fabricbreaking After 4th After 6th strength, lbs.

75-min. 75-min. Run Additive wash wash Warp Fill Blank 50 30. 9 23. 5a.. Nazsiog 0.2 1.3 32.5 29.4 Ethylene bis-(sodium 0. l 34. 27. 5

Dithiocarbamate. 0 Na CO 27.8 33.8

tion A for 5 seconds, pressing to remove excess liquid, immersion insolution B for 5 seconds, pressing to remove excess liquid, washing inwarm water containing a small amount of detergent, rinsing in plainwater, air drying, semi-decating to give a flat set.

Samples of the products were tested for shrinkage, using the standardwash procedure described above. Also, to measure their flat setcharacter, the samples, after such standard wash procedure and whilestill damp, were placed flat on a table and observed under obliquelighting conditions (to highlight wrinkles, etc.). Samples of theproducts were tested also for breaking strength. The results obtainedare tabulated below:

Having thus described the invention, what is claimed is:

1. In the process wherein fibrous textile material having disulphidebonds is subjected to serial impregnation with (I) a solution of adiamine in water and with (II) a solution of a bifunctional organiccompound capable of forming a polymer with said diamine, the saidcompound being dissolved in an inert, volatile, water-immisciblesolvent, the improvement which comprises incorporating in said solution(I) a sulphur-containing, reductive, disulphide-splitting agent.

2. In the process wherein wool is subjected to serial impregnation with(I) a solution of a diamine in water and with (II) a solution of abifunctional organic com- Conc. of Area shrinkage Fabric breaking Cone.of sodium after [our strength, lbs. HMDA, carbonate, Reducing agent and75-min. washes, Flat setting Run percent percent concentration thereofpercent Warp Fill rating 1 1 (blank) None None None 1 42. 2 30. 9 23. 51 2 (control).. 2 4 o 32. 8 34. 3 28. t) 2 3 2 4 Na2S.9H O, 0.6%. 20. 733. 5 25. 8 3 4... 2 4 NflzS.9Hg0, 1.2%... 14. 0 34. 5 28.5 4 5... 2 4Na2S.9H20, 2.4%... 4. 5 34. 6 26. 5 5 6... 1 None NazS.9HgO, 4.8% 0.831. 7 26. 3 5 7 2 4 B-Mercaptoethanol, 0.4%. 0 35. 4 26. 7 4 8. 2 4B-Mercaptocthanol, 1.6%....- 6. 9 30. 3 27. 6 5 9 2 4 Na thioglycollatc,1'7 0. 8 33. 5 27. 0 4 1 2 None Na thioglycollate, 5% 1. 2 32. 2 .24. S4

1 In this case, the shrinkage stated (42.2%) was after the first 75-min.wash. 2 Flat setting character of the samples was rated on the basis:l=poor to 5=excellcnt.

EXAMPLE 2 Comparison of sodium metasilicate and sodium carbonateSolution A.--Aqueous solution containing 2% hexamethylene diamine and 2%sodium metasilicate. Solution A .-Aqueous solution containing 2%hexaunethylene diamine and 2% sodium carbonate. Solution B.3% Sebacoylchloride in a petroleum distillate (Stoddard solvent).

An all-wool worsted fabric was treated, in continuous operation, in thefollowing manner: Immersion in solution A or A for 5 seconds, pressingto remove excess liquid, immersion in solution B for 5 seconds, pressingto remove excess liquid, washing in warm water containing a small amountof a detergent, rinsing in plain water, and drying in air.

Samples of the products were tested for shrinkage, using the standardwash procedure described above. The results are tabulated below:

pound capable of forming a polymer with said diamine, the said compoundbeing dissolved in an inert, volatile, water-immiscible solvent, theimprovement which comprises incorporating in said solution (I) asulphur-containing, reductive, disulphide-splitting agent.

3. In the process wherein wool is subjected to serial impregnation with(I) a solution of a diamine in water and with (II) a solution of adiacid chloride dissolved in an inert, volatile, water-immisciblesolvent, the improvement which comprises incorporating in said solution(I) a sulphur-containing, reductive, disulphide-splitting agent.

4. The process of claim 3 wherein said sulphur-containing, reductive,disulphide-splitting agent is an alkali metal sulphide.

5. The process of claim 3 wherein said sulphur-conraining, reductive,disulphide-splitting agent is an alkali metal thioglycollate.

Area shrhikage, percent After 1st After 2nd After 3rd After 4th After6th -min. 75-min. 75-min. 75-min. 75-min. Run Additive wash wash washwash wash 1 Sodium metasilicate 0. 3 0. 8 1. 0 1. 2 1. 3 2 Sodiumcarbonate 1v 8 4. 2 7. 8 11. 2 N.D.

N.D.Not determined.

EXAMPLE 3 6. The process of claim 3 wherein said sulphur-contain-Solution A.An aqueous solution containing 0.2 molar ing, reductive,disulphide-splitting agent is ,B-mercaptohcxamethylene diamine plus oneof the following ad- 75 ethanol.

7. In the process wherein fibrous textile material is subjected toserial impregnation with (I) a solution of a diamine and (II) a solutionof a bifunctional organic compound capable of forming a polymer withsaid diamine, the said compound being dissolved in an inert, volatile,water'immiscible solvent, the improvement which comprises incorporatingin said solution (I) an alkali-metal silicate.

8. In the process wherein wool is subjected to serial impregnation with(I) a solution of a diamine and (II) a solution of a bifunctionalorganic compound capable of forming a polymer with said diamine, thesaid compound being dissolved in an inert, volatile, water-immisciblesolvent, the improvement which comprises incorporating into saidsolution (I) an alkali metal silicate.

9. In the process wherein wool is subjected to serial impregnation with(I) a solution of a diamine and (II) a solution of a diacid chloridedissolved in an inert, volatile, water-immiscible solvent, theimprovement which comprises incorporating into said solution (I) analkali metal metasilicate.

10. In the process wherein fibrous textile material is subjected toserial impregnation with (I) a solution of a diamine in Water and ('II)a solution of a bifunctional organic compound capable of forming apolymer with said diamine, the said compound being dissolved in aninert, volatile, water-immiscible solvent, the improvement whichcomprises incorporating in said solution (I) a dithiocarbamate.

11.1In the process wherein wool is subjected to serial impregnation with(I) a solution of a diamine in water and (II) a solution of abifunctional organic compound capable of forming a polymer with saiddiamine, the said compound being dissolved in an inert, volatile,water-immiscible solvent, the improvement which comprises incorporatingin said solution (I) a dithiocarbamate.

12. In the process wherein wool is subjected to serial impregnation with(I) a solution of a diamine in water and (II) a solution of a diacidchloride dissolved in an inert, volatile, water-immiscible solvent, theimprovement which comprises incorporating in said solution (I) ethylenebis-(sodium dithiocarbamate).

References Cited UNITED STATES PATENTS 2,508,713 5/1950 Harris et a18l27.6 2,955,016 10/1960 Moore 8128 3,049,445 8/1962 Lundgren et a1.8-l28 X 3,051,544 8/1962 Wolf et a1 8l28 3,078,138 2/1963 Miller et a18128 NORMAN G. TORCHIN, Primary Examiner I CANNON, Assistant ExaminerUS. Cl. X.R.

1. IN THE PROCESS WHEREIN FIBROUS TEXTILE MATERIAL HAVING DISULPHIDEBONDS IS SUBJECTED TO SERIAL IMPREGNATION WITH (I) A SOLUTION OF ADIAMINE IN WATER AND WITH (II) A SOLUTION OF A BIFUNCTIONAL ORGANICCOMPOUND CAPABLE OF FORMING A POLYMER WITH SAID DIAMINE, THE SAIDCOMPOUND BEING DISSOLVED IN AN INERT, VOLATILE, WATER-IMMISCIBLESOLVENT, THE IMPROVEMENT WHICH COMPRISES INCORPORATING IN SAID SOLUTION(I) A SULPHUR-CONTAINING, REDUCTIVE, DISULPHIDE-SPLITTING AGENT.